Manufacture of adhesives or binders.



WALTER H. DICKERSON, OF MUSKEGON, MICHIGAN.

MANUFACTURE OF ADHESIVES R BINDEBS.

No Drawing.

' To all whom it may concern:

liquor.

Be it known that I, WALTER H. IDICKER- SON, a citizen of the United States, residing at Muskegon, in the county of Muskegon and State of Michigan, haveinvented certain new and useful Improvements in the Manufacture of Adhesives or Binders, of

which the following is a. specification.

This invention relates to the manufacture or' production of compositions of matter having adhesive or binding properties from liquors such as result from the manufacture of paper pulp cellulose by the sulfite process, which liquors are commonly termed waste sulfite.v liquor or waste All processes in use heretofore for the treatment of waste sulfite liquor for the production of an adhesive binder, particularly for the use in binding sand together for the manufacture of cores in foundry work, have involvedthe neutralization of the waste liquor by means ofniilk of'lime or caustic lime or other caustics, this neutralization being necessary because evaporation or concentration has been effected iniron evaporating apparatus. It has also previously been considered necessary to have waste sulfite liquor in a neutral or alkaline condition in order to 80 evaporate it without decomposition.

I' havenow discovered. however, that a binding compound made from waste sulfite liquor which has been suitably'concentrated but not neutralized or made alkaline by caustics or milk of lime, has superior binding qualities to those made from liquors which have been neutralized or made alkaline. I have found also that concentration 'or evaporation of acid reacting liquors and without decomposition thereof, can be effected' in a copper lined vacuum evaporator, especially if the liquor is not heated too long during evaporation.

The straight waste sulfite liquor when conoentrated in its natural condition gives a material having very good binding properties, such-as are required for sand core ap paratus, but it, at the same time, contains a high percentage of sulfurous acid. This high acid content is obiectionable to the workman, either, during the baking of the 7 cores or during the pouring of the metal into the molds.

The removal of this acid content by complete neutralization of the acids with a suflicient amount of caustic al- Specification'of Letters Patent.

Patented Jan. 7, 1919.

-' Application filed January 10, 1913. Serial No. 741.215.

kalis or excess thereof results in the production of inferior adhesive or binding compounds, however. This appears to be due to the fact that in neutralizing or making alkaline with caustic alkalis certain constituents of the waste sulfite liquor undergo certain alterations orchanges. The deterioration of the compound as regards its binding "property, resulting from such neutralization of the acids of the waste sulfite liquors, has been so great that it has been proposed and advised that certain other materials such as molasses, flour or glue should be added to the compound so as to increase its adhesive properties.

In order to produce adhesive or binding compounds from waste sulfite liquors, which per cent. of unneutralized acid in the 85 straight or partially concentrated liquors. In this way only the sulfurous. acid of-the liquor is neutralized, whereas the organic acids are retained in their natural state. Commercial calcium carbonate, or' refuse lime cake carrying a high percentage ofcala cium carbonate, may be suitably used for this purpose, but barium carbonate or magnesium carbonate or any other relatively in soluble carbonate or similar suitable compounds, such as aluminum hydrate, could be used. Practical consideration dictates calcium carbonate as the 'best material because of its cheapness, for example.

Because of the insolubility or weakly al- 100 kaline nature. of the reagents the liquor or resulting concentrated compound will always remain slightly acid and will not show any of the characteristics. such as darkening or decomposition, which follow neutrali- 105 'zation or even partial neutralization with milk of lime or other caustic alkalis. The -use of such alkalis invarlably causes such decompositions as a result of the permanent alkalinity of the neutralized liquors 110 or the temporary alkalinity thereof resulting from local overneutralization of portions of the liquor before stirring is completed. I avoid such temporary or permanent overneutralization of the liquors by using relatively insoluble, weakly acid compounds, such as carbonates, instead of caustic alkalis and in amounts not quite sufiicient to neutralize all of the acids in the liquor.

In practice I employ various methods of carrying out this general procedure. Thus the waste liquor, as it is received hot from the digesters, may be treated with the proper amount of calcium carbonate determined by analysis as above specified, and after the precipitation of insoluble calcium sulfitev which will result has settled out, the resulting liquor may be evaporated, preferably in a vacuum evaporator,to a concentration of 30 Baum, or so that it will contain 50% of solids; it will then be ready for use as a binding compound. Of course the evaporation could be carried to complete dryness whenever a solid compound which is afterward to be moistened or dissolved was considered preferable.

Instead of adding all of the calcium carbonate before evaporation, as above, the

waste liquor may be partially concentratedto say 12 Baum; the acid content may be then determined and a suflicient quantity of calcium carbonate be then added, followed by separation from the precipitate and completion of the evaporation as above described. This latter method of procedure is to be preferred, because in the first lace much of the acid is removed from the liquor during preliminary evaporation in the form of sulfur-dioxid gas and with the result that less calcium carbonate is required to be added. In the second place the latter procedure is not accompanied to as great a degree by a precipitation of insoluble calcium compounds 1n the evaporator and consequent incrustation or scaling of the interior or tubes of the evaporator. If the calcium carbonate is added before any concentration whatsoever, the precipitation of insoluble calcium compounds is not so nearly complete outside of the evaporator, but occurs in part during the evaporation and with the consequence just mentioned.

Of course a portion of the total necessary amount of calcium carbonate determined by analysis may be added to the hot waste liquors before any evaporation, and the remaining portion of calcium carbonate may be added after partial evaporation to say 12 or even 30 Baum. I do not find these two latter methods of procedure to be as satisfactory, however, as that just above explained.

The adhesive or bindinf compounds, or solutions thereof, obtame by my method posed and considered. necessary. My prod act is accordingly less expensive to manufacture although of equal or greater effectiveness than those heretofore known.

It may be used, of course, for any binding purposes, including use as a binding material for sand cores, and as a binding material for road construction or road dressing purposes. The product is characterized also by the fact that it is able to precipitate glue solutions.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. The method of treating waste sulfite liquor for the preparation of an adhesive product, which consists in adding a water insoluble neutralizing agent in an amount insufficient to neutralize all of the acid, and concentrating to a suitable degree.

2. The method of treating waste sulfite liquor for the preparation of an adhesive product, which consists in concentrating it to a suitable degree and adding during the concentration a water insoluble neutralizing agent in an amount insufficient to neutralize all of the acid. a a

3. The method of treating waste sulfite liquor for the preparation of an adhesive product, which consists in adding a water insoluble neutralizing agent in an amount insufiicient to neutralize all of the acid, and concentrating in vacuo to a suitable degree.

4. The method of treating waste sulfite liquor for the preparation of an adhesive product, which consists in concentratindg it in vacuo to a suitable degree nd ad ing during the concentration a water insoluble neutralizing agent in an amount insuficient to neutralize all of the acid.

5. The method of treating waste sulfite liquor for the preparation of an adhesive product, which consists in adding calcium carbonate in an amount insufiicient to neutralize all of the acid, and concentrating to a suitable degree.

6. In an adhesive product consisting of the concentrated and undecomposed conorganic and colloidal and mass unaltered by having added to the liquor a water insoluble neutralizing agent,

by being substantially free from inorganic acids.

8. An adhesive product consisting of the concentrated and undecomposed constituents of an incompletely neutralized mass of Waste sulfite liquor, characterized as having the organic constituents of the mass unaltered by-having added to the liquor a watery insoluble neutralizing agent, and by being clearly soluble in Water and substantially free from inorganic acids.

9. An' dhesive product consisting of the concentrated and undecomposed constituents of an incompletely neutralized mass of waste sulfite liquor, characterized as having the constituents of the mass unaltered I by having added to the liquor a water insoluble neutralizing agent, and by being clearly soluble in Water and substantially free from inorganic acids.

10. An adhesive product obtained from undecomposed waste sulfite liquor characterized as being a concentrated incompletely neutralized mass having the colloidal constituents unaltered by having added to the' liquor a water insoluble neutralizing agent leaving the organic acids free, and by being substantially free from sulfurous acid.

11. An adhesive product obtained from undecomposed waste sulfite liquor characterized as being a concentrated incompletely neutralized mass having the colloidal constituents unaltered by having added to the liquor a water insoluble neutralizing agent leaving the organic acids free, and clearly soluble in Water and substantially free from sulfurous acid.

In testimony whereof I aflix'my signature in the presence'of two witnesses. p

WALTER H. DICKERSON.

Witnesses:

L. S. PERRINE, LAURA'E. SMITH.

by being 

